title: Effect of storage time and dietary enzyme on the metabolizable energy and digesta viscosity of barley-based diets for poultry.
abstract: The effect of barley storage time and dietary enzyme addition on the energy value of barley-based broiler diets was studied in two experiments. A two-rowed winter barley (Beka cultivar) was stored at room temperature for 0, 3, 6, 16, and 32 wk after harvesting. At these dates, diets were formulated using 50% barley with and without the addition of a commercial beta-glucanase-based enzyme product. In Experiment 1, 320 Arbor Acres chickens (eight replicates of three 10-d-old birds and eight replicates of one 30-d-old bird, per treatment) were fed the experimental diets to determine the AMEn following a 2 x 2 x 5 (age by enzyme by barley storage time) factorial design. At the end of the metabolism trial, viscosity of the intestinal contents was determined in 30-d-old broilers. Total beta-glucan, nonstarch polysaccharides (NSP), in vitro viscosity, and endogenous enzyme activity of barley grain decreased with increasing storage time. Dietary AMEn increased with barley storage time (from 2,755 to 2,939 kcal/kg DM, P < 0.001, for 0 and 32 wk of storage, respectively), with enzyme addition (2,861 vs 2,919 kcal/kg DM, P < 0.003), and with the age of animals (2,826 and 2,958 kcal/kg DM for 10- and 30-d-old chickens, respectively, P < 0.001). Interactions of enzyme and age by barley storage time (P < 0.02 and P < 0.001, respectively) were also detected. These data indicate that the minimum time of barley storage before its inclusion in broiler feed depends on the animals' age (more than 6 wk for 10-d-old chickens and 3 wk for 30-d-old chickens), and that the use of enzymes allowed a reduction in the time of barley storage. Digesta viscosity decreased with barley storage time (P < 0.001), and with enzyme addition (P < 0.001), an interaction of storage time by enzyme addition was shown (P < 0.007). Digesta viscosity was also negatively related to the dietary AMEn content (r = -0.68, P < 0.01). In vitro barley viscosity explained 53 and 90% of the variation in gut viscosity produced by unsupplemented and enzyme supplemented diets, respectively. In Experiment 2, the same diets as Experiment 1 and the barley grain were intubated into 120 adult roosters (Hy-Line) to determine TMEn. Dietary and barley TMEn values were not affected by barley storage time or enzyme addition (3,237 and 3,037 kcal TMEn/kg DM for diets and barley, respectively).
authors.affiliation: Trouw Nutrition España S.A. Ronda de Poniente, Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Fuente
authors.forename: P
authors.initials: P
authors.lastname: Perez de Ayala
authors.forename: A
authors.initials: A
authors.lastname: Flores
authors.forename: M J
authors.initials: MJ
authors.lastname: Villamide
mesh_terms: D000821:Animal Feed; D000818:Animals; D001230:Aspergillus; D002645:Chickens / Q000502:physiology*; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology*; D004734:Energy Metabolism; D005511:Food Handling / Q000379:methods; D005766:Gastrointestinal Contents; D006026:Glycoside Hydrolases; D001467:Hordeum; D008297:Male; D013997:Time Factors; D014242:Trichoderma; D014783:Viscosity; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases; D001617:beta-Glucosidase
chemical_list: D006026:Glycoside Hydrolases; D014995:Xylosidases; D001617:beta-Glucosidase; D043325:Xylan Endo-1,3-beta-Xylosidase